Create only a single user account and specify a VL for it, there you go, exactly the same as before.

Can you clarify how to do this, please? I can't figure it out without requiring a login. I have only a fraction of my books that I can legally share, so previously I just made them a virtual library and never had to worry about the others appearing on the content server. Now they all appear, and it looks like the only way to stop that from happening is to move to user accounts with passwords, right? Ideally I could avoid that, but I don't want to risk sharing things I shouldn't, either. Thanks.

I don't see any way to specify a Virtual library for a user, a simple library yes, but I don't see any selection for the virtual libraries, or a place to enter them.

And if it's a search specification that needs to be added, then how to give a user access to more than one virtual library within the same master library?

In V2 i handled this via proxies in the web server going to different instances of the calibre server running on different ports.

You can provide an arbitrary search expression for each library visible to a user. If your virtual libraries are defined using a saved search then you can provide the same saved search to the content server.

You cannot give a single user access to more than one "virtual library". This is exactly the same as the calibre V2 content server.

In V3 you must use different users to give access to different virtual libraries. This is really no different than using different ports in V2. Instead of connecting to different ports, one connects with different user IDs.

Appreciate everyone's help and insight. Our server is not open to the internet, just a (mildly) large intranet. I'm probably just more paranoid than most around here about not sharing things I shouldn't. I can distribute passwords to our users, it just seemed the other way was "safer," but maybe that's just me. Great program! Thanks!

I don't need advice on how this is "not secure". To the contrary, opening a port to a server and using passwords is not secure enough for me. I run a VPN into my home network, and set up VPN client-specific firewall rules for who can access what (internal IP address and port). This is all based on the client certificate, which is much more secure than any Calibre password would ever be.

So I don't need passwords for Calibre's content server to create security. I already have a superior version of security. Is there a way to configure Calibre's content server without passwords? I could just not set up content server "users", because then it could be password-less, but I want to have users to control which virtual library can be accessed. Apparently, the only way to control virtual library access is to configure users. And if you configure a user, then you are required to configure a password. This is over-restrictive. Well intentioned maybe, but still over restrictive for folks that want to create security by a different method.

Related (somewhat), ... is there a way to configure default content server behavior? I would like to have the following default start up behavior for all incoming users: (1) No password required, (2) Go to a specific virtual library, (3) Display all items - do not require repeated clicks to "display more", (4) Sort by author, then series, then order in series, (5) Allow quick access to select from a specific subset of tags to cut down the list size.

I know that's asking for a lot. But it's the way I would want to default things in my personal version of "the ideal content server".

I'm afraid I am not going to ever add a way to have users without passwords. It would be ripe for abuse.

As for having default virtual library and sort settings simply bookmark the URL of the book list page showing books with whatever state you want. Then tell your users to go directly to that URL instead of to the top level. If you put the calibre server behind a reverse proxy then you cn even have the reverse proxy redirect to that URL automatically. So no need for user accounts. But note that you will still need user accounts for things like making changes to the calibre library (which will be implemented soon) or cross device last read and annotations syncing.